1. Field of the Invention
The application relates to a sleeve for treating obesity, and, more particularly, to a sleeve placed in the duodenum to limit absorption of food.
2. Background of the Related Art
The duodenum is the proximal portion of the small intestine extending from the pylorus to the jejunum. It is the shortest path of the small intestine where most chemical digestion takes place, and is typically between 10-15 inches long. The superior part of the duodenum is connected to the liver. The inferior part passes to the left. The pancreatic duct and common bile duct enter the descending part of the duodenum thought the major duodenal papilla. The ascending part of the duodenum joins with the jejunum at the duodenojejunal flexure.
Inside the duodenum occurs the mixing of acid chyme from the stomach, bile from the liver and gallbladder, pancreatic juice and intestinal juices. The entry of acid chyme into the duodenum brings about discharge of bile from the gallbladder and the secretion of pancreatic juice by the pancreas.
The duodenum is largely responsible for the breakdown of food in the small intestine, using enzymes. The duodenum also regulates the rate of emptying the stomach via hormonal pathways. Secretin and cholecystokinin are released from cells in the duodenal epithelium in response to acidic and fatty stimula present there when the pylorus opens and releases gastric chyme into the duodenum for further digestion. These cause the liver and gall bladder to release bile, and the pancreas to release bicarbonate and digestive enzymes such as trypsin, lipase, and amylase into the duodenum as needed.
The incidence of obesity continues to increase worldwide. Obesity has been defined in terms of a body mass index greater than 30, with body mass index defined by weight in kilograms divided by the square of the height in meters. (Overweight is defined as a body mass index of over 25). Obesity can cause a number of serious health conditions such as hypertension, diabetes, certain forms of cancer, coronary artery disease, stroke, congestive heart failure, and venous disease. Obesity can also cause orthopedic problems, skin problems and respiratory difficulties.
A variety of methods are currently being utilized to treat obesity. In general, these procedures fall into two categories: procedures which restrict food intake or procedures which alter the anatomy of the small intestine or divert the peristalsis of a person's food intake past the small intestine to decrease caloric absorption.
Some methods are designed to reduce the stomach by partition or bypass such as by stapling or tying off portions of the large or small intestine or stomach to reduce the amount of food desired by the patient, and the amount absorbed by the intestinal tract. In gastric banding, an adjustable band is placed externally of the stomach to constrict a portion of the stomach. Such treatments are designed to reduce the caloric intake of the individual by more rapidly triggering the satiety impulse or limiting the amount of food the individual can ingest. Complications can occur as the individual, due to the stomach restriction, may not be intaking sufficient nutrients.
Laparoscopic methods of banding and vertical banded gastroplasty have been developed, which although provide the advantages of minimally invasive surgery compared to open surgery, are complicated to perform and oftentimes cannot be utilized, as well as can lead to adverse effects due to long term failure to ingest sufficient nutrients.
Additionally, many of these surgical procedures for treating obesity have the disadvantage of being irreversible.